Global warming, deforestation, fires combined could hasten Amazon demise, study finds

Bogota, February 14

Drought and heat driven by climate change and other factors threaten to cause the collapse of South America’s lush Amazon rainforest system, scientists said on Wednesday in a study that found that nearly half of it could be pushed to a tipping point by 2050.

“The region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system,” the researchers wrote in the study published in the journal Nature.

The researchers estimated that 10 to 47 per cent of Amazon’s current forest cover will face these combined stressors by 2050.

“Once we cross this tipping point, maybe we cannot do anything anymore,” said ecologist Bernardo Flores of the University of Santa Catarina in Brazil, lead author of the report. “The forest will die by itself.”

It is time, Flores added, to declare a “red alert” for the Amazon, the world’s largest tropical rainforest.

With warming temperatures sapping the region of moisture, the rainforest is steadily turning into savannah or other forms of degraded ecosystems more likely to burn in wildfires, according to experts. This transformation marks a major change for the Amazon, where most fires now are fanned by ranchers or farmers clearing land. As the land dries out, more wildfires could erupt as they do in the drier pine forests of the US.

The new research “shows how close the Amazon forest is to a tipping point,” said climate scientist Carlos Nobre of Brazil’s University of Sao Paulo, who was not part of the study. Deforestation is exacerbating the risk, with fewer trees generating moisture that rains back down to nourish the forest.

Already, about 18 per cent of the Amazon rainforest has been destroyed, according to Nobre. If that figure reaches 20 to 25 per cent, Nobre said, the forest overall could shift to savannah.